1. Field of Invention
The present invention relates to a hinge, and more particularly to a hinge that can be positioned accurately.
2. Description of the Related Art
An electronic appliance such as a laptop or a mobile phone has a base, a cover and a hinge. The cover connects to the base and may have a camera lens. The hinge is usually mounted between the base and the cover, pivots to open or close the cover and rotates the cover relative to the base, so the camera lens on the cover is able to rotate and to face different directions.
With reference to FIGS. 5 and 7, a conventional hinge is mounted between a base and a camera lens of an electrical appliance and comprises a hollow barrel (70) and a combination leaf-pivot pin (80).
The barrel (70) is attached to the camera lens and has a through hole and a hollow C-shaped positioning sleeve (71). The through hole is formed coaxially through the barrel (70) and has a surface. With further reference to FIG. 6, the positioning sleeve (71) is resilient, is mounted in the through hole of the barrel (70) and has an inner surface and an expansion slot (711). The expansion slot (711) is formed longitudinally through the positioning sleeve (71). The surface has at least one flat surface (712). One flat surface (712) is formed longitudinally on the surfaceopposite to the expansion slot (711), and another flat surface (712) may be coincident with the expansion slot (711).
The combination leaf-pivot pin (80) is mounted rotatably in the barrel (70) has a leaf and a pivot pin. The leaf is attached to the cover of the electrical appliance and has an inner end. The pivot pin is formed on and protrudes longitudinally from the inner end of the leaf, is mounted in the barrel (70) and has a positioning ring (81). The positioning ring (81) is formed coaxially on the pivot pin, is mounted in the positioning sleeve (71) and has an outer surface and two flat surfaces (811). The flat surfaces (811) are formed opposite to each other on the outer surface of the positioning ring (81), selectively correspond to and mate with the flat surface (712). Each flat surface (811) has two sides.
When the camera lens rotates, the barrel (70) rotates relatively to the combination leaf-pivot pin (80). When the flat surfaces (811) on the positioning ring (81) rotate and detach from the flat surface (712) in the positioning sleeve (71), the positioning sleeve (71) will expand. When the camera lens is positioned, the flat surface (811) on the positioning ring (81) will enter and mate with the flat surface (712) in the positioning sleeve (71) and act as a detent, and the positioning sleeve (71) will retract, so users will feel the camera is positioned.
However, before one flat surface (811) on the positioning ring (81) enters the flat surface (712) in the positioning sleeve (71), the side of the opposite flat surface (811) on the positioning ring (81) will sink into the expansion slot (711), and the positioning sleeve (71) will contract a little. Users easily believe that the camera lens is positioned and stop rotating the camera, so users will be confused.
To overcome the shortcomings, the present invention provides a hinge to mitigate or obviate the aforementioned.